Exemplary embodiments of the present disclosure relate to a gas turbine, and more particularly, to a cooling apparatus of a gas turbine in which a torque tube unit is configured to be separable into a plurality of individual units and the torque tube unit is provided with a cooling air supply passage to supply cooling air required for cooling of a turbine disk unit, thereby performing cooling.
Generally, a gas turbine is a kind of motor that obtains a torque by injecting combustion gas to blades of the turbine and may be largely divided into a compressor, a combustor, and a turbine. The compressor is supplied with some of power generated from a rotation of the turbine to serve to compress introduced air at a high pressure, in which the compressed air is delivered to the combustor.
The combustor mixes the compressed air with fuel and combusts the mixture to generate a flow of high-temperature combustion gas and injects the generated high-temperature combustion gas to the turbine and allows the injected combustion gas to rotate the turbine, thereby obtaining a torque.
Here, the compressor and the turbine include a plurality of turbine disks having the blades radially coupled with an outer peripheral portion thereof. Generally, the compressor includes a larger number of turbine disks than the number of turbines. Hereinafter, the plurality of turbine disks disposed in the compressor is called a compressor section and the plurality of turbine disks disposed at the turbine side is called a turbine section.
The respective turbine disks are fastened to rotate along with the adjacent turbine disks. For example, the respective turbine disks are coupled to deliver the rotation torque between the adjacent turbine disks by using the coupling scheme called the Hirth coupling. Further, the respective turbine disks are fixed using a tie rod.
The tie rod is inserted to penetrate through centers of the respective turbine disks and may be fastened to prevent the turbine disks from moving in a shaft direction by pressure nuts fastened to both ends of the tie rod.
Meanwhile, the combustor is disposed between the compressor section and the turbine section, and therefore the compressor section and the turbine section are spaced apart from each other to form a space in which the combustor is disposed and a torque transfer member that may deliver the rotation torque generated from the turbine section to the compressor section is additionally mounted in the gas turbine.